In the field of photography, a photographer is often confronted with scenes that have extreme imaging properties, such as high dynamic range and unusual color balance. Dynamic range typically refers to a ratio between maximum and minimum values of physical measurement, and in photography specifically refers to a ratio of luminance values. Color balance typically refers to a comparative ratio of intensities of colors in an image.
Examples of scenes with extremes in imaging properties include scenes with high dynamic range or unusual color balance. In some cases, such a scene may have multiple different regions, each with different brightness levels or a different color balance. For example, a scene might include a first region depicting bright day light and a second region depicting dark shadow. In this situation, the first region depicting bright day light has a different brightness level and a different color balance than the second region depicting dark shadow.
When confronted with such a scene, the photographer is often compelled to capture many images of the scene, each with different exposure settings, such as shutter speed and/or color balance. Then in post-capture image processing, the photographer combines the images into an acceptable rendition of the scene. This acceptable rendition may not be achievable due to loss of information during capture, such as saturated channels, that cannot be easily estimated or reconstructed.